10 | | * ~~`U_init_dim_obs`~~: The name of the user-supplied routine that provides the size of observation vector |

11 | | * ~~`U_obs_op`~~: The name of the user-supplied routine that acts as the observation operator on some state vector |

12 | | * ~~`U_init_obs`~~: The name of the user-supplied routine that initializes the vector of observations |

13 | | * ~~`U_prodRinvA`~~: The name of the user-supplied routine that computes the product of the inverse of the observation error covariance matrix with some matrix provided to the routine by PDAF. This operation occurs during the analysis step of the SEIK filter. |

14 | | * ~~`U_init_obsvar`~~: The name of the user-supplied routine that provides a mean observation error variance to PDAF (This routine will only be executed, if an adaptive forgetting factor is used) |

| 10 | * [#U_init_dim_obsinit_dim_obs.F90 U_init_dim_obs]: The name of the user-supplied routine that provides the size of observation vector |

| 11 | * [#U_obs_opobs_op.F90 U_obs_op]: The name of the user-supplied routine that acts as the observation operator on some state vector |

| 12 | * [#U_init_obsinit_obs.F90 U_init_obs]: The name of the user-supplied routine that initializes the vector of observations |

| 13 | * [#U_prodRinvAprodrinva.F90 U_prodRinvA]: The name of the user-supplied routine that computes the product of the inverse of the observation error covariance matrix with some matrix provided to the routine by PDAF. This operation occurs during the analysis step of the SEIK filter. |

| 14 | * [#U_init_obsvarinit_obsvar.F90 U_init_obsvar]: The name of the user-supplied routine that provides a mean observation error variance to PDAF (This routine will only be executed, if an adaptive forgetting factor is used) |